Control of Microbial Growth - 1 Flashcards
Destroys all microorganisms on a surface
Sterilization
Defined as the destruction of all pathogenic and spoilage organisms that can grow in food under normal storage and handling conditions
Still has the possibility of contamination
Commercial sterilization
the agent of botulism in canned foods
Clostridium botulinum
a rare but serious illness caused by a toxin that attacks the body’s nerves and causes difficulty breathing, muscle paralysis, and even death
Botulism
Greek word for decay
Sepsis
Absence of contamination
Asepsis
Used to prevent contamination of surgical instrument, personnel, and patient during surgery
Also used in the food industry
Aseptic techniques
Chemicals that inhibit the growth of bacteria but does not kill them
Bacteriostiatic agent
Suffix: ___ = to stop
stasis
Agent that kills certain microoganisms
Germicide
Kills bacteria but not endospores
Bacteriacide
Inactivates or destroys viruses
Viricide
Kills fungi
Fungicide
Kills endospores
Sporocide
The act of removing toxins
Decontamination
The act of substantially reducing microbial presence
Sanitation
The removal of vegetative or non-endospore-forming pathogens
Can be physical or chemical
Reduces the presence of microorganisms
Disinfection
a chemical substance or compound used to inactivate or destroy microorganisms on inert (non-living) surfaces
Disinfectant
an antimicrobial substance or compound that is applied to living tissue to reduce the possibility of sepsis, infection or putrefaction.
Antiseptic
Mechanical removal of most microbes
Ex: alcohol swab on skin
Degerming
Use of chemical agent on food-handling equipment
Ex: soap and water
Sanitization
What are some early practices done to control microbial growth?
Salting, smoking, pickling, drying, exposure of food and clothing to sunlight
Use of spices to mask taste and spoilage of food
Antiseptic technique
Semmelweis
Medical application of sanitization
Used carbolic acid on surgery equipment
Lister
Germ theory
Pasteur
Steam sterilization
Pioneer of aseptic surgery
Bergmann
Sterile rubber gloves
From John Hopkins University
Halstead
The cause of death of over 10% of surgeries
An infection that happens at the hospital
Nosocomial infection
Factors of the rate of microbial death
Number of microbes
Types of microbes
Environmental influences - the presence of organic material
Time of exposure
the presence of organic material
Environmental influences
the use of high temperatures to denature microbial enzymes and other proteins
Heat -
Types of Control
Positive and Negative
this type of control includes industrial fermentation, beer, wine, breadmaking
Positive control
this type of control includes by physical or chemical means, including the use of antibiotics
Negative control
The control of microbial growth is either to ___ or ___ microbes.
kill or inhibit
the lowest temperature all microbes in a liquid suspension will be killed in 10 minutes
Thermal Death Point
minimal length of time all bacteria will be killed
Thermal Death Time
the time 90% of bacteria is killed
Used in canning
Decimal Reduction Time
coagulates microbial proteins and dentures their proteins through the use of moist heat
More effective than dry heat
Moist Heat
kills or inactivates viruses, bacteria, protozoa, and other pathogens by using heat to damage structural components and disrupt essential life processes
is not sterilization and is more accurately characterized as pasteurization
Temperature of around 100 - 200 degrees Celsius
Boling
A virus that can survive up to 30 minutes of boiling
Hepatitis Virus
Can survive up to 20 hours or more of boiling
Endospores
Sterilizes through the use of hot steam under pressure
Kills microbes within 15 minutes
121 degrees Celsius at twice the force of atmospheric pressure
Autoclave
Way of preventing the spoilage of beverages
Pasteurization
pasteurization at around 65 degrees Celsius for 30 minutes
Classic/Vat method
Pasteurization Methods:
Classic/Vat method
High-Temperature Short-Time Pasteurization (Flash Pasteurization)
Ultra High Temperature
pasteurization at around 72 degrees Celsius for 15 seconds
High-Temperature Short-Time Pasteurization (Flash Pasteurization)
pasteurization at 140 degrees Celsius for 3 seconds then vacuum sealed and cooled
Milk can then be stored for 25 days at room temperature
Ultra High Temperature
kills microorganisms by oxidizing molecules
Dry Heat
This method is mostly used on inoculating loops/needles
Direct Flame
Typical method of dealing with biological waste
Incineration
The use of an oven for 2 hours at around 170 degrees Celsius
Hot Air Sterilization
___ = the hottest part of the Bunsen burner flame
1870 degrees Celsius
Dry heat transfers heat more?/less? effectively to a cool body than most heat.
less
Filtration through a screenlike material
Direct Filtration
Types of Direct Filtration:
High-Efficiency Particulate Air Filters
Membrane Filters
filtration used in operating rooms and burn units
High-Efficiency Particulate Air Filters
filtration that has a uniform pore size
Used in industry and research
Membrane Filters